In wireless communication represented by a wireless LAN complying with the IEEE802.11 standard series, there are many setting items to be set in advance. The setting items include wireless parameters necessary for wireless communication, such as an SSID as a network identifier, an encryption scheme, an encryption key, an authentication scheme, and an authentication key. It is very troublesome for a user to manually set them.
Various manufacturers have proposed automatic setting methods for easily setting wireless parameters in a wireless apparatus. In those automatic setting methods, one apparatus provides another apparatus with wireless parameters using a procedure predetermined between these connected apparatuses and a message, thereby automatically setting the wireless parameters.
As for the wireless parameter automatic setting method, each manufacturer often employs its own method. Procedures for setting wireless parameters or interpretable messages are different between apparatuses which do not support a common wireless parameter automatic setting method. In this case, it is impossible to set wireless parameters using the automatic setting method. On the other hand, between apparatuses which support a common wireless parameter automatic setting method, it is possible to easily set wireless parameters using the automatic setting method.
In recent years, game machines and household appliances are also provided with a wireless function. Some of them not only execute communication within a network managed by a wireless base station, but also establish ad hoc connection for directly connecting the devices and communicating with each other without intervening the base station.
Japanese Patent Laid-Open Nos. 2003-338821 and 2004-266870 disclose examples of wireless parameter automatic setting.
To start communication between a wireless base station and a wireless communication terminal, the wireless communication terminal participates (joins) in a network which has been already created by the base station, starts wireless parameter setting, and acquires wireless parameter information from the base station.
However, in ad hoc connection for direct communication between devices, the devices create different networks since each device can create a network by itself. As a result, the devices may not communicate with each other. Each device, therefore, has to start communication using parameters (temporary parameters for setting) such as a specified SSID and frequency. After the devices create a single network, they need to communicate with each other to acquire formal wireless parameters and to set the acquired wireless parameters.
The above-mentioned temporary parameters for setting are commonly used for the devices. If the temporary parameters leak to a third party, the wireless parameters also leak, and security problems arise.
When an undesired device starts wireless parameter setting accidentally at the same time, information about wireless parameters may be erroneously exchanged with that device. Furthermore, unlike transfer between a base station and a wireless communication terminal, a wireless parameter setting scheme in ad hoc connection does not uniquely define the transfer direction of wireless parameters.
This requires a user to select a network in which the user participates (joins) and the transfer direction of parameters. A problem that the operability of the user deteriorates arises.
The above problems may arise not only for wireless parameters but also for wired communication parameters which need to be set for communication between devices.